Classifications

• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
  • C10G29/00—Refining of hydrocarbon oils, in the absence of hydrogen, with other chemicals
  • C10G29/20—Organic compounds not containing metal atoms
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D19/00—Degasification of liquids
  • B01D19/0005—Degasification of liquids with one or more auxiliary substances
  • B01D19/001—Degasification of liquids with one or more auxiliary substances by bubbling steam through the liquid
  • B01D19/0015—Degasification of liquids with one or more auxiliary substances by bubbling steam through the liquid in contact columns containing plates, grids or other filling elements
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
  • C10G29/00—Refining of hydrocarbon oils, in the absence of hydrogen, with other chemicals
  • C10G29/20—Organic compounds not containing metal atoms
  • C10G29/205—Organic compounds not containing metal atoms by reaction with hydrocarbons added to the hydrocarbon oil
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
  • C10G31/00—Refining of hydrocarbon oils, in the absence of hydrogen, by methods not otherwise provided for
  • C10G31/06—Refining of hydrocarbon oils, in the absence of hydrogen, by methods not otherwise provided for by heating, cooling, or pressure treatment
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D2256/00—Main component in the product gas stream after treatment
  • B01D2256/24—Hydrocarbons
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D2257/00—Components to be removed
  • B01D2257/60—Heavy metals or heavy metal compounds
  • B01D2257/602—Mercury or mercury compounds
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
  • C10G2300/00—Aspects relating to hydrocarbon processing covered by groups C10G1/00 - C10G99/00
  • C10G2300/10—Feedstock materials
  • C10G2300/1033—Oil well production fluids
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
  • C10G2300/00—Aspects relating to hydrocarbon processing covered by groups C10G1/00 - C10G99/00
  • C10G2300/10—Feedstock materials
  • C10G2300/1037—Hydrocarbon fractions
  • C10G2300/104—Light gasoline having a boiling range of about 20 - 100 °C
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
  • C10G2300/00—Aspects relating to hydrocarbon processing covered by groups C10G1/00 - C10G99/00
  • C10G2300/10—Feedstock materials
  • C10G2300/1037—Hydrocarbon fractions
  • C10G2300/1044—Heavy gasoline or naphtha having a boiling range of about 100 - 180 °C
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
  • C10G2300/00—Aspects relating to hydrocarbon processing covered by groups C10G1/00 - C10G99/00
  • C10G2300/10—Feedstock materials
  • C10G2300/1037—Hydrocarbon fractions
  • C10G2300/1048—Middle distillates
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
  • C10G2300/00—Aspects relating to hydrocarbon processing covered by groups C10G1/00 - C10G99/00
  • C10G2300/20—Characteristics of the feedstock or the products
  • C10G2300/201—Impurities
  • C10G2300/205—Metal content

Definitions

• the disclosure generally relates to removing mercury from crude oils.
• Coal is the largest source of human-generated mercury emissions in the United States. Coal-fired power plants release about 48 tons of mercury annually, according to EPA data. In contrast, the total amount of mercury in crude oil processed in the U.S. annually is less than five percent of the amount contained in U.S. coal produced and consumed annually.
• This disclosure is directed to a relatively inexpensive, robust and simple process for removing mercury that is not significantly affected by the crude oil compositional variations.
• a synthetic reducing agent is added to and mixed with a crude oil (or other type of hydrocarbon matrix) that contains various forms of mercury.
• the mixed composition is then heated to convert the various forms of mercury in the crude oil into elemental mercury during a mercury conversion process.
• the synthetic reducing agent acts as a catalyst for this conversion reaction. This allows lower conversion temperatures and pressures to be used. Further, the synthetic reducing agent is able to accelerate the mercury conversion in slow reacting matrices, such as light condensates.
• This process allows for the removal of all mercury forms at a moderate conversion temperature and within a commercially feasible timeframe.
• the lower conversion temperature reduces the capital and operating expenses that would be required for building and operating a mercury removal unit, while maintaining or increasing the output of reduced-mercury or mercury-free hydrocarbons.
• this reducing agent and process is also applicable to most hydrocarbon matrices such as natural gases, condensates, naphthas, middle distillates, and waxes.
• the synthetic reducing agent converts all forms of mercury, including ionic mercury, into elemental mercury using an organic phosphite (P(OR)3).
• organic phosphite reducing agents are relatively inexpensive chemicals that are commonly available worldwide in bulk quantities.
• the use of organic phosphite reducing agents also facilitates mercury conversion in otherwise difficult matrices such as condensates and refined petroleum products.
• the phosphite can have any alkyl or phenyl substituents, including methyls, ethyls, propyls, butyls, phenyls, and the like.
• Exemplary phosphites include triphenyl phosphite, tributyl phosphite, dibutyl phosphite, triethyl phosphite, diethyl phosphite, trimethyl phosphite, dimethyl phosphite or combinations thereof.
• a combination of R groups with different numbers of carbons in their chain length can be used on the phosphite (i.e. P(OR)(OR')(OR”)) as well as having a hydrogen in place of at least one R group.
• the most preferred phosphite is dimethyl phosphite ((OMe)2P(0)H).
• reaction rate expressions specific to the crude oil feed developed in US 9574140, users can calculate optimum design specifications such as process temperature, vessel sizes, oil feed rate, synthetic reducing agent feed rate, etc. for commercial-scale mixing units.
• the heating occurs for a time sufficient to convert at least 95% all mercury forms to elemental mercury.
• 96, 97, 98, 99 or nearly 100% of the mercury is converted.
• the amount of time needed is variable, because the reaction rate depends on the type of hydrocarbon, the composition of the forms of mercury, the conversion temperature and the amount of reducing agent.
• the elemental mercury is transferred from the oil phase into a gas phase by, preferably, flashing or gas stripping, but any other method of removal can be used, and the various methods can be combined.
• the removing of the elemental mercury from the gas phase after the conversion process can be by any known in the art or to be developed in the future, and in addition to the above, includes condensation, precipitation, or absorption, adsorption, and combinations thereof.
• elemental mercury can be removed by precipitation as HgS.
• Another method includes treating the mercury rich stream with an adsorption agent. Yet another method includes removing mercury from the mercury rich stream by precipitation as HgSe after contacting the mercury rich stream with a filter containing selenium. If desired, some or all of the stripping gas can be recycled back into the process to save costs.
• Elemental mercury means Hg 0+ , which is a metallic, silvery liquid that readily breaks into droplets and easily vaporizes at room temperature. Elemental mercury is not the only volatile form of mercury, and the term does not include inorganic or organic forms of mercury.
• ionic mercury refers to mercury(II) or Hg 2+ . Ionic mercury is very soluble in crude oils and is a non-volatile form of mercury. Elemental mercury, in contrast, is less soluble in crude oils and more volatile.
• the reducing agent can convert other non-volatile forms of mercury, such as Hg(CH3)2 (dimethyl mercury), HgCEbX (monomethyl mercury), that are commonly found in hydrocarbons into element mercury.
• phase "conversion of mercury to elemental mercury” or “conversion of mercury in various forms to elemental mercury” means that all of the various forms of mercury found in the hydrocarbon matrix are converted to elemental mercury. This includes all non-volatile forms of organic mercury and ionic mercury, and any other forms that may be present.
• Hg° elemental mercury (can exist in gaseous, liquid, or solid phases)
• Hg 2+ compiex organically-complexed ionic mercury (mercury-thiols, etc.)
• Hgads mercury adsorbed to solid particles or metallic surfaces
• FIG. 1 Literature values of concentrations of mercury in crude oil, from Hollebone 2007.
• FIG. 2 Schematic of a process for removal of mercury from crude oil.
• FIG. 3 Ionic to elemental mercury conversion in crude oil with various concentrations of dimethyl phosphite as the reducing agent. The reaction time was 5 minutes.
• FIG. 4 Decrease in the ionic mercury reduction reaction temperature in crude oil with increasing amounts of dimethyl phosphite as the reducing agent.
• FIG. 5 Comparison of relative reaction rate in direct response to increasing dimethyl phosphite concentration.
• the invention provides a novel method of removing all forms of mercury from hydrocarbon sources. Specifically, a synthetic reducing agent comprising a phosphite is added to a hydrocarbon source containing various forms of mercury. The hydrocarbon/phosphite mixture is then heated to convert the various forms of mercury to elemental mercury, which can then be removed from the hydrocarbon source.
• the present methods includes any of the following embodiments in any combination(s) of one or more thereof:
• [0055] A method of removing mercury from a hydrocarbon wherein a synthetic reducing agent is mixed with a hydrocarbon comprising mercury in various forms, then heated to at least 100°C and less than 200°C until at least 95% of the mercury in various forms is converted to elemental mercury. The elemental mercury can then be converted to gaseous elemental mercury before removal from the hydrocarbon/reducing agent mix.
• the hydrocarbon can be mixed with a synthetic reducing agent, then heated to about 100-200°C, depending on the conversion information, until at least 90% of the mercury in various forms is converted to elemental mercury, as calculated using the reaction rate expression.
• the elemental mercury can then be converted to gaseous elemental mercury before removal from the hydrocarbon/reducing agent mix.
• the gaseous elemental mercury can then be stripped from the hydrocarbon stream by contacting the stream with gas stream, such as nitrogen, methane, ethane, propane, butane, natural gas or combinations thereof. This results in a treated liquid hydrocarbon stream and a mercury rich gas stream.
• gas stream such as nitrogen, methane, ethane, propane, butane, natural gas or combinations thereof.
• the mercury can there be removed from the mercury rich gas stream by precipitation as HgS if the gas stream contains hydrogen sulfide.
• mercury can there be removed from the mercury rich gas stream by precipitation as HgO.
• a method of removing mercury from a hydrocarbon that contains various forms of mercury wherein the hydrocarbon is fed into a mixer at a predetermined flow rate, along with an organic phosphite that is also fed into the mixer at predetermined flow rate.
• the hydrocarbon and organic phosphite can then be mixed, and fed into a thermal soak vessel.
• the mixture can be heated in the thermal soak vessel to at least 100°C and less than 200°C until at least 90 wt% of the mercury in various forms is converted to elemental mercury.
• the elemental mercury can then be converted to gaseous elemental mercury before removal from the hydrocarbon/reducing agent mix.
• the synthetic reducing agent is an organic phosphite and can be selected from a group including, but not limited to, triphenyl phosphite, tributyl phosphite, dibutyl phosphite, triethyl phosphite, diethyl phosphite, trimethyl phosphite, dimethyl phosphite, ethyl methyl phosphite, or combinations thereof. Dimethyl phosphite is preferred.
• heating range in the above methods is expected to fall between 100 and less than 200°C. Depending on the type of hydrocarbon, heating ranges can include 100°C-180°C or 120-150°C. However, it can also be less than 100°C, e.g, 95°, 90°, 85°, or even 80°, depending on crude components, amount of mercury, and plant design considerations.
• the elemental mercury can be converted to gaseous elemental mercury by flashing or gas stripping.
• the gaseous elemental mercury can then be removed by condensation, precipitation, or absorption, adsorption, or combinations thereof.
• the hydrocarbon can be most hydrocarbon matrices, including but not limited to crude oil, natural gases, condensates, naphthas, middle distillates, and waxes.
• Hg 2+ is very soluble in crude oils and is a non-volatile form of mercury, making its removal more difficult.
• preheating oils to about 100°C or 100- 200°C with a phosphite will convert Hg 2+ to Hg°, and simplify extraction because processes to remove elemental mercury already exist.
• US4962276 and US8080156 disclose processes that employ gas stripping to remove mercury from condensates and crude oils. These processes, however, only work if the mercury is already in the gas strippable elemental form. As noted above, a significant portion of the mercury in a crude oil can be present in the non-volatile ionic form, and the non-volatile ionic mercury cannot be removed from a crude oil by gas stripping. Each of these methods can be used however, if proceeded by the preheat stage described herein, which converts various forms of mercury to elemental mercury.
• US5384040 discloses a catalytic process for transforming mercury compounds contained in a gas condensate liquid into elemental mercury. Although not the preferred embodiment, a non-catalytic heat treatment process in the absence of hydrogen is also disclosed. The elemental mercury formed by the catalytic process is removed from the gas condensate liquid using a solid phase sorbent.
• the extent of mercury reduction in a given hydrocarbon matrix is therefore a function of the reaction temperature, the chemical composition of the reducing agent, the reducing agent concentration, and the length of time that the oil is allowed to react.
• FIG. 2 A block flow diagram of the disclosed mercury removal process is shown in FIG. 2.
• a mercury-containing crude oil and the reducing agent is introduced into an in-line mixer to be mixed. From there, the mixed composition is introduced into a heater to quickly and efficiently preheat the crude oil to at least 100°C.
• the heated oil is then moved into a thermal soak vessel that is heated to a predetermined temperature above 100°C.
• the crude remains in the heated soak vessel while the mercury species are being converted into elemental mercury.
• the crude oil flows into a gas-stripping vessel with an optional packing therein to facilitate contact between a stripping gas and crude oil.
• the stripping gas flows from the bottom of the vessel through the oil.
• Any gas such as nitrogen, methane, ethane, propane, butane, or natural gas, can be used.
• the elemental mercury is removed in the form of mercury gas.
• the stripping gas plus mercury vapor is drawn from the top of the vessel and passed through a mercury removal unit, wherein the mercury can be removed from the stripping gas using an adsorption method (filter or scrubber).
• mercury can be removed from the stripping gas via precipitation with a filter containing selenium or a gas containing hydrogen sulfide.
• the mercury-free stripping gas can then be recycled.
• the stripped crude oil will be discharged for further processing.
• Speciation of the mercury provides information for understanding the fate and distribution of mercury throughout the petroleum system from reservoir rock to consumer products and how to structure the conversion.
• Each of the mercury species is characterized by a unique set of properties that define its toxicity, solubility, volatility, thermal stability, and reactivity.
• the amount of reducing agent, mixing times, and conversion temperature and time used in the process depicted in FIG. 2 should be augmented for the relative concentrations of various mercury species in a given hydrocarbon source to improve efficient conversion inexpensively.
• Kinetic data for the mercury reduction reaction were obtained by spiking the oil with an enriched stable isotope of ionic mercury (e.g. 198 Hg 2+ or 201 Hg 2+ ).
• an enriched isotope in the form of HgCh or HgO for example, is dissolved in the oil and the rate of conversion of this ionic mercury standard to elemental mercury is monitored as a function of time and temperature.
• the use of an enriched isotope allows the reduction reaction to be monitored accurately even though naturally -occurring mercury may also be present in the oil.
• results of the kinetic measurements can be used to define a reaction rate expression for a specific oil that might have a form such as:
• FIG. 3 depicts the increase in mercury conversion at lower reaction temperatures and increasing concentrations of the reducing agent, dimethyl phosphite. Each reaction was 5 minutes long. As expected, the higher concentration reducing agent (200 ppm) reached at least a 90% conversion efficiency at a much lower temperature than the reaction without any reducing agent.
• reaction temperature was at least 40°C less. This is very useful because higher reaction temperatures can lead to degradation of hy drocarbon components or the loss of lower molecular weight hydrocarbons due to evaporation.
• the reducing agent can be utilized to reduce the temperature needed for the conversion process, such that thermal degradation of hydrocarbons and/or evaporation of lighter weight hydrocarbons less problematic.
• FIG. 4 illustrates the decrease in reaction temperature after the addition of the synthetic reducing agent for a conversion efficiency of 95%.
• the reducing agent significantly lowers the reaction temperature compared to crude oil with no addition.
• the reaction temperature is lowered by about 70°C.
• FIG. 5 illustrates the relative effect of reducing agent concentration on the rate of the ionic mercury conversion reaction.
• the method can be applied to any hydrocarbon source. Lower molecular weight hydrocarbons such as those contained in condensates have inherently slow mercury conversion rates. By adding a reducing agent to these feedstocks, commercially attractive processing rates can be achieved.

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• Oil, Petroleum & Natural Gas (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Engineering & Computer Science (AREA)
• General Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Production Of Liquid Hydrocarbon Mixture For Refining Petroleum (AREA)

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• 2018
  • 2018-08-01 CA CA3072894A patent/CA3072894C/en active Active
  • 2018-08-01 WO PCT/US2018/044804 patent/WO2019036194A1/en unknown
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